Action for Children campaign: victims of emotional child abuse delivered a letter to the Prime Minister in November

Helen Donohoe, who has been director of public policy for the charity for over four years, called the announcement a milestone in what she described as an example of a "relatively quick" success in campaigning for a change in the law.

The charity started work in 2011 on calling for the legal definition of child abuse to be expanded from physical and sexual to emotional, Donohoe told PRWeek.

"It's about changing the way we treat children as a society and recognising that emotional abuse has an incredibly damaging effect across their whole lives. If this becomes law then in 10, 20, 30 years' time it should culturally change the way we approach childhood."

Since obtaining a Government review last year, the charity has been winding down its political engagement, but Donohoe is aware it may need to do more to build public support for the change.

"Reading the comments beneath the media coverage of the Government’s plans I was surprised by how against the idea even Guardian readers were," she said.

"We did not go into this with a view to criminalising parents [but] it's a line that the media have gone with this morning. As soon as you start talking about a law that makes it illegal to emotionally neglect children what you get in your head is more parents being thrown in jail."

She admitted that the charity needed to do more on the public relations front, saying: "We need to put our heads together and think about what we will do over the next few months. There's an opportunity here for us to be positive and start talking about what makes a really good childhood."

However, she stressed that Action for Children had produced a credible case for politicians to take action.

"The priority when we started this was for us to have a really solid evidence base – it was about talking to police officers, social workers, teachers and my colleagues. It was not just us sitting in our central London office number-crunching.

"Then we recognised we had to stand back from being what people perceive to be a self-interested pressure group and let the serious politicians do the talking.

"We set up an independent advisory group chaired by Tory peer Baroness Butler-Sloss who is one of the leading legal experts in this area. That made for a much easier path in Parliament. That sense of 'Oh, here comes another pressure group knocking on my door,' wasn't there because we had peers talking to peers."

The proposal was backed by the Education Select Committee last year, leading justice minister Damian Green to announce a review of the law in the autumn.

The Government will introduce the change in the Queen's Speech in early June.